A/B Switcher: Presonus, Mackie?

I am looking for an A/B switcher that will allow me to use various sources and monitors. Two of the units that are in my price range are the Presonus Central Station and the Mackie Big Knob. It would be great to hear some opinions on these units. Here are some of my concerns and maybe you guys can debunk them.

1. Do they offer truly transparent sound?
2. Do they have crosstalk problems?
3. Is one more robust than the other?
4. Are there any "gotchas" that I should be aware of?
5. Are there better options in the $500 and below range?

Thanks. The Presonus has some useful features that the Big Knob doesn't such as a SPDIF digital input. So I was leaning towards getting it if the concensus is that the sound is transparent. That's good to know you have had a positive experience with it.

The Presonus works great EXCEPT that with the two units I have had here the cue output is OUT OF PHASE to the input and speaker outputs which will cause problems to people singing with headphones. Check my post about AKG headphones and absolute phase..... Switching is silent and the only odd thing I have noticed is that because it is passive, when you switch in the sub (spkr C) the mains (A&B) decrease in volume slightly. Love the meters and cal option, and the remote is cool.

This will strictly be used as a way to switch between two audio inputs and possibly at some point have a second set of monitors to A/B with. It sounds like with that scenario I will have no problems. Everyone seems to be happy with the quality and that is a key for me.

I thought the street price on this is about $800 which puts it out of my range. It does look like a nice product, especially the precise stepped attenuation. But the Presonus is half the money and people seem happy with the quality.